The invention concerns a support tube for a filter element wherein the support tube encloses an interior and a filter medium surrounds annularly the support tube. The support tube comprises a plurality of, in particular straight, webs that are partially connected with each other and form a hollow-cylindrical grid structure that surrounds a cylindrical interior. Through openings are formed by at least three webs or web sections that are connected to each other, wherein fluid can flow radially relative to the center axis of the hollow-cylindrical grid structure through the through openings.
DE 10 2010 010 964 A1 discloses a support grid for a filter element. The support grid has at one end a thread for mounting it on a filter housing. When it is screwed onto the filter housing or unscrewed, the support grid transmits torsion forces from the end where the operator is grips it for turning it to the other end which has the thread.
Because of the partially high loads occurring upon mounting and demounting, the webs of the support grid must have a sufficiently large cross-section for force transmission so that the cross-section of the through openings between the webs that is available for flow is reduced and the pressure loss of the filter element is increased.
The object of the invention is to provide a support tube which is resistant to torsion loads and bending loads and enables a minimal pressure loss.